I’ve increasingly come around to the view that Shostakovich’s greatest achievement is his vocal music—for that reason the 14th is my favourite of his symphonies but some of the other orchestral song cycles (& songs with piano/chamber accompaniment) are equally good.
In this respect I guess he’s also comparable to Mahler, of whom my favourite symphonic work is probably Das Lied von der Erde, and whose songs in general are consistently superlative whereas his symphonies are sometimes a bit uneven from movement to movement etc.
But I have generally come to like the symphonies a good deal despite their unevenness or whatever, even “weaker” entries like numbers 3 and 12. I think only 5, 7 and 10 still haven’t done much for me at this point, whereas I do enjoy all of the others to varying extents.